88 SALT-WATER FISHES 



of seizing a bream or mackerel already hooked, but this is not 

 observed in the case of the porbeagle, though it often takes 

 the large bait of pilchard or mackerel intended for bass or 

 pollack. It is also alleged, though such a statement seems to 

 conflict with its normal laziness of habit, to bite the artificial 

 tinned spinning baits off the " plummeting " lines, which are 

 used from boats going under sail to catch inshore mackerel. 

 The evidence of this habit must, however, rest on the 

 somewhat frequent discovery of these baits in the porbeagle's 

 stomach, together with the known fact of large fish of some 

 kind often breaking away with them. These large fish can 

 never be caught in the act, for the gear used for mackerel has 

 to be so fine that a heavy fish like a porbeagle would at once 

 sever the lower third of the line. It may be, therefore, that 

 the porbeagle is occasionally aroused from its customary 

 lethargy and pursues the spinning bait, particularly when the 

 boat comes up to the wind and the progress is momentarily 

 checked ; but it seems more probable that some extra large 

 mackerel, or even a small pollack, breaks away with the bait, 

 and is then swallowed by a porbeagle, the tin spinner baffling 

 the shark's digestion and remaining as evidence of its meal. 

 This explanation is put forward with all reservation, but not 

 without some little acquaintance with the habits of the shark 

 in question. 



The exact manner and season of the porbeagle's breeding 

 were long doubtful, but it is probable that it brings forth living 

 young, like the vast majority of our sharks, and that the 

 breeding takes place during the colder months, when the shark 

 is absent from our coasts. For the latter conclusion, the fact 

 of no porbeagle having been caught in our seas, recently at 

 any rate, with any trace of unborn young is responsible. 

 Both Day and Couch appear to have omitted all reference to 

 the very offensive odour of this shark, a scent which resides 

 more particularly in the blood. 



The Thresher {^Alopias vulpes) is easily recognised by the 



